DAK2 4.28 - FOW not working for allied off-map boxes

I am starting a campaign with a friend and we would love to use the FOW characteristics of module version 4.28.

While doing the setup for scenario 7.5 with the preset that comes with the module, we noticed the allied units in Greece, Sudán, Dead and Removed boxes are visible and actionable to the axis player even when the option “Display of pieces in off-map boxes” is set to “invisible”.

Is this a known bug?. Is there a fix for it?. Other FOW functions seem to work as expected.

Thank you very much in advance,